[bug report] wifi: ath12k: resource leak in ath12k_dp_srng_setup()

[Dan Carpenter]

Hello Kalle Valo,

The patch d889913205cf: "wifi: ath12k: driver for Qualcomm Wi-Fi 7
devices" from Nov 28, 2022, leads to the following Smatch static
checker warning:

drivers/net/wireless/ath/ath12k/dp.c:310 ath12k_dp_srng_setup() warn: 'ring->vaddr_unaligned' from dma_alloc_coherent() not released on lines: 298,305.

drivers/net/wireless/ath/ath12k/dp.c
    217 int ath12k_dp_srng_setup(struct ath12k_base *ab, struct dp_srng *ring,
    218                          enum hal_ring_type type, int ring_num,
    219                          int mac_id, int num_entries)
    220 {
    221         struct hal_srng_params params = { 0 };
    222         int entry_sz = ath12k_hal_srng_get_entrysize(ab, type);
    223         int max_entries = ath12k_hal_srng_get_max_entries(ab, type);
    224         int ret;
    225 
    226         if (max_entries < 0 || entry_sz < 0)
    227                 return -EINVAL;
    228 
    229         if (num_entries > max_entries)
    230                 num_entries = max_entries;
    231 
    232         ring->size = (num_entries * entry_sz) + HAL_RING_BASE_ALIGN - 1;
    233         ring->vaddr_unaligned = dma_alloc_coherent(ab->dev, ring->size,
    234                                                    &ring->paddr_unaligned,
    235                                                    GFP_KERNEL);
    236         if (!ring->vaddr_unaligned)
    237                 return -ENOMEM;
    238 
    239         ring->vaddr = PTR_ALIGN(ring->vaddr_unaligned, HAL_RING_BASE_ALIGN);
    240         ring->paddr = ring->paddr_unaligned + ((unsigned long)ring->vaddr -
    241                       (unsigned long)ring->vaddr_unaligned);
    242 
    243         params.ring_base_vaddr = ring->vaddr;
    244         params.ring_base_paddr = ring->paddr;
    245         params.num_entries = num_entries;
    246         ath12k_dp_srng_msi_setup(ab, &params, type, ring_num + mac_id);
    247 
    248         switch (type) {
    249         case HAL_REO_DST:
    250                 params.intr_batch_cntr_thres_entries =
    251                                         HAL_SRNG_INT_BATCH_THRESHOLD_RX;
    252                 params.intr_timer_thres_us = HAL_SRNG_INT_TIMER_THRESHOLD_RX;
    253                 break;
    254         case HAL_RXDMA_BUF:
    255         case HAL_RXDMA_MONITOR_BUF:
    256         case HAL_RXDMA_MONITOR_STATUS:
    257                 params.low_threshold = num_entries >> 3;
    258                 params.flags |= HAL_SRNG_FLAGS_LOW_THRESH_INTR_EN;
    259                 params.intr_batch_cntr_thres_entries = 0;
    260                 params.intr_timer_thres_us = HAL_SRNG_INT_TIMER_THRESHOLD_RX;
    261                 break;
    262         case HAL_TX_MONITOR_DST:
    263                 params.low_threshold = DP_TX_MONITOR_BUF_SIZE_MAX >> 3;
    264                 params.flags |= HAL_SRNG_FLAGS_LOW_THRESH_INTR_EN;
    265                 params.intr_batch_cntr_thres_entries = 0;
    266                 params.intr_timer_thres_us = HAL_SRNG_INT_TIMER_THRESHOLD_RX;
    267                 break;
    268         case HAL_WBM2SW_RELEASE:
    269                 if (ab->hw_params->hw_ops->dp_srng_is_tx_comp_ring(ring_num)) {
    270                         params.intr_batch_cntr_thres_entries =
    271                                         HAL_SRNG_INT_BATCH_THRESHOLD_TX;
    272                         params.intr_timer_thres_us =
    273                                         HAL_SRNG_INT_TIMER_THRESHOLD_TX;
    274                         break;
    275                 }
    276                 /* follow through when ring_num != HAL_WBM2SW_REL_ERR_RING_NUM */
    277                 fallthrough;
    278         case HAL_REO_EXCEPTION:
    279         case HAL_REO_REINJECT:
    280         case HAL_REO_CMD:
    281         case HAL_REO_STATUS:
    282         case HAL_TCL_DATA:
    283         case HAL_TCL_CMD:
    284         case HAL_TCL_STATUS:
    285         case HAL_WBM_IDLE_LINK:
    286         case HAL_SW2WBM_RELEASE:
    287         case HAL_RXDMA_DST:
    288         case HAL_RXDMA_MONITOR_DST:
    289         case HAL_RXDMA_MONITOR_DESC:
    290                 params.intr_batch_cntr_thres_entries =
    291                                         HAL_SRNG_INT_BATCH_THRESHOLD_OTHER;
    292                 params.intr_timer_thres_us = HAL_SRNG_INT_TIMER_THRESHOLD_OTHER;
    293                 break;
    294         case HAL_RXDMA_DIR_BUF:
    295                 break;
    296         default:
    297                 ath12k_warn(ab, "Not a valid ring type in dp :%d\n", type);
    298                 return -EINVAL;

ring->vaddr_unaligned not released on error path.

    299         }
    300 
    301         ret = ath12k_hal_srng_setup(ab, type, ring_num, mac_id, &params);
    302         if (ret < 0) {
    303                 ath12k_warn(ab, "failed to setup srng: %d ring_id %d\n",
    304                             ret, ring_num);
    305                 return ret;
    306         }
    307 
    308         ring->ring_id = ret;
    309 
--> 310         return 0;
    311 }

regards,
dan carpenter